In a magnetic disk device, in order to perform seek control of magnetic heads, the amount of manipulation is obtained using a model, which simulates a control target (model-following seek control). Also, in order to increase a data area in which user data is written, there is a method of dividing servo patterns into a plurality of zones from the inner circumference of the magnetic disk toward the outer circumference thereof, and raising a write frequency (reference frequency) of servo patterns of zones of the outer circumference with respect to zones of the inner circumference.